The first step is to access the Help Me! menu. To get this press the following 3 keys at the same time:
ALT CAPS H (at the same time)
Note: For Pearl and other Sure-type phones press and hold the ALT key (Bottom left) and type E A C E, for Storm, hold the BACK arrow, and tap the screen in the following areas: TOP LEFT, TOP RIGHT, TOP LEFT, TOP RIGHT.
You should be presented with a screen like the one shown below:

Type the PIN, App Version and Uptime in the form here: Blackberry eScreen Key Generator
Now simply type the KEY directly on to that screen. Nothing will appear when typing. For numbers hold the ALT key when typing. Now you should be in the engineers menu - if you are not please try again ensuring the data you entered in the eScreen Key Generator is EXACTLY as displayed on your BlackBerry. If you close the screen ensure you change the Uptime on the eScreen Key Generator.
Navigate to OS Engineering Screens as shown below:

Now scroll down to Device Info, select and then down until you see MEP-XXXXX-XXX as shown below:

You now have your MEP number, please provide this for us to unlock your phone - Click here to unlock.